Molecular cloning and characterization of rat chitotriosidase.

Recent year some members of mammalian chitinases and chitinase-like proteins have been discovered, but rat counterpart of human and mouse chitotriosidase has not been identified. Moreover, the physiological functions of mammalian chitinases are not very clear. To facilitate the studies we cloned the cDNA encodes the rat chitotriosidase. The results revealed that it is differ from mouse and human chitotriosidase genes, it exist alternative splicing transcripts in several tissues we detected due to different transcriptional initiation sites and different exon usage, although all the open reading frame of these cDNAs predict a protein of 464 amino acids with a typical chitinase structure, including a signal peptide, a highly conserved catalytical domain and a chitin-binding structure. The predicted amino acid sequence is highly homologous to that of mouse and human chitotriosidase. Recombinant expression of the cloned cDNA demonstrated that the encoded protein is secreted extracellularly and has chitinolytic activity.